1. Technical Field
The present invention relates to a yellow ink composition, an ink set including a cyan ink composition, a yellow ink composition, and a magenta ink composition, which are used for an ink jet recording, and an ink jet recording method in which printing is performed by depositing a reaction solution and an ink composition to a recording medium.
2. Related Art
Ink jet recording is a printing method in which droplets of an ink composition are ejected and deposited onto a recording medium, such as paper, to conduct printing. A feature of this method is that an image having high resolution and high quality can be printed at a high speed with relatively inexpensive apparatuses.
In general, ink compositions for use in ink jet recording each contain water as a main component, a coloring agent, and a wetting agent, such as glycerol, for preventing clogging. Water-soluble dyes are often used as coloring agents used in ink compositions for ink jet recording because of their high saturation, the wide variety of types of coloring agents available, their good water solubility, and the like.
Dye, however, may have poor properties such as low water resistance and lightfastness. Thus, materials printed with dye ink compositions may have poor water resistance and lightfastness. Use of specialized ink-jet paper having an ink-absorbing layer results in improvement in water resistance. In the case of using plain paper, however, materials printed with dye ink compositions have insufficient water resistance.
Pigments have water resistance and lightfastness superior to dyes. To improve water resistance and lightfastness, the use of pigments as coloring agents used in ink compositions for ink jet recording has recently been examined. Pigments are generally insoluble in water. To use pigments in aqueous ink compositions, it is thus necessary to stably disperse pigments in water and then prepare ink compositions including the pigments. Examples of an aqueous pigment ink include an aqueous pigment ink containing a pigment dispersed by a surfactant or a polymeric dispersant, an aqueous pigment ink containing self-dispersible pigment particles having water-dispersible functional groups on surfaces of the particles, and an aqueous pigment ink containing colored fine particles in which pigment particles are covered with a water-dispersible resin.
When consideration is given to the use of pigments as coloring agents in inks for ink jet recording, although pigments have water resistance and lightfastness superior to dyes, the number of types of available coloring agents is smaller than that of dyes. In the case of practically using pigments as coloring agents in inks for ink jet recording, hues also need to be sufficiently investigated in addition to lightfastness and water resistance. For example, JP-A-2000-345080 discloses a yellow ink composition having a combination of a specific pigment having excellent lightfastness and two specific pigments having excellent color developability. JP-A-10-120956 discloses that the use of an ink set having a combination of cyan, magenta, and yellow ink compositions containing specific pigments results in a good image, in particular, an image having a good hue, lightfastness, and water resistance.